Stereo image matching technology for obtaining a three-dimensional stereoscopic image is a technology of extracting stereoscopic image information from two images input through cameras mounted left and right. The stereo image matching technology obtains a stereo image by capturing the same subject by using two cameras that are disposed at different positions on the same line. The stereo image matching technology may be considered as a process of calculating a distance up to the subject by detecting which a pattern at a specific position within the image captured by one camera is present at a certain position within the image captured by the other camera and extracting a difference between two positions, that is, disparity.
The stereo image matching technology in a dynamic program type according to the related art replaces the stereo image obtained from the stereo cameras (left camera and right camera) with an image positioned at a central line of both cameras in a row unit so as to obtain the three-dimensional stereoscopic image.
The stereo matching technology according to the related art independently processes each row and does not consider a relationship between upper rows or lower rows at the time of processing each row. Therefore, when calibration of the left and right cameras is accurate, no problem is caused. However, when an epipolar line is distorted due to the inaccuracy of the calibration of the left and right cameras, a steak noise in which a horizontal stripe appears in the image may be caused.
Actually, it is difficult to accurately match the calibration of the left and right cameras and since there is a unique error between the left and right cameras, it is difficult to completely solve the phenomenon.
In addition, since the stereo matching technology according to the related art is designed under the premise that only brightness information in the image information of the left and right cameras is used and the image brightness of the left and right cameras matches each other, the image matching error may be caused when brighter light is incident on the specific camera between the left and right cameras.